Fastener driving interlocking pistol or tool



Aug. 28, 1962 3,050,732

FASTENER DRIVING INTERLOCKING PISTOL 0R Toor.

P. TERME-r Fili-.ed Nov. 24, 1958 2 Sheets-Sheet 1 lNvEm/f )DIERRE TER/GET Y Aug. 28, 1962 P. TERMET 3,050,732

FASTENER DRIVING INTRLOCKING PISTOL OR TOOL Filed Nov. 24, 1958 2 Sheets-Sheet 2 FIG. 5

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MVr/17M P /ERRE TER m ET MLM WMJ HM BSJBZ Patented Aug. 28, 1962 3,050,732 FASTENER DRIVING INTERLGCKWG PISTOL 0R T001.

Pierre Ter-met, 16 Impasse Belloeuf, Lyon 3, France Filed Nov. 24, 195,8, Ser. No. 775,951 Claims priority, application France Nov. 29, 1957 3 Ciaims. (Cl. 1-445) The present invention relates to improvements in fastener driving tools adapted to drive fasteners, studs or the like workpiece materials.

The present invention is particularly concerned with improvements applicable to fastener driving pistols or tools, wherein the gases produced by the explosion of an explosive cartridge cause an intermediate piston to be propelled and strike the fastener or stud contained in the pistol to drive the former into the workpiece in the same manner that a nail is driven by a hammer stroke.

in the devices known up to the present day, whether of this or any other type, it was indispensable to use cartridges having different explosive powers, selected on the one hand as a function of the hardness of the material into which one desired to drive the fastener or stud, and on the other hand according to the desired fastener penetration depth.

According to the present invention, there has been provided a power adjustment or control device whereby it is possible to use a standard explosive cartridge having a predetermined explosive power, and the adjustment or control of said device permits the regulation of the force acting on said fastener or stud -according to the material into which it is to be driven.

Such power adjustment or control device according to the present invention is essentially characterized by the fact that the pistol tiring chmber containing a loaded cartridge is closed by `a rod integral with the piston driving the fastener into the material. As soon as the explosion occurs, the rod integral with the piston moves and uncovers a variable cross-section orifice through whichl a portion of the gases resulting from the cartridge explosion may be evacuated to the outside surrounding atmosphere.

Said power adjustment or control is obtained on the one hand by varying the cross-sectional area of the orifice through which gases are allowed to escape outside, and on Ithe other hand by varying the iiring chamber volume prior to tiring the cartridge.

According to the present invention, gas escapes outside the pistol, thus permitting the control of the power thereof as it flows between the cartridge holder and a cylinder element in which the piston moves, said cylinder element being displaceable in an axial direction with respect to the cartridge holder by means of a threading.

it is an object of this invention to provide a device adapted for holding said fastener, stud or the like in a fixed position within the pistol barrel, said device-being essentially characterized by having a plurality of magnets arranged in a longitudinal direction around said barrel and contained in a support member made from a nonmagnetic material.

It is yanother object of this invention to provide a device adapted to maintain at the pistol barrel muzzle' end attachment members intended to be lixed in the workpiece material by means of a fastener, stud or the like, said device being essentially characterized by the fact that it comprises at the pistol barrel muzzle end a recess the shape of which mates with that of said attachment member intended to be fixed, and said recess having at the bottom thereof one or more magnets adapted to maintain said attachment members in a xed position.

ln order that the present invention may be more fully unders-tood and carried into practice, the same will be now described in an illustrative and by no means limitative manner of the scope of this invention las claimed in the appended claims, and with reference to the annexed drawings, in which:

PIG. 1 is au elevation view in longitudinal section o a fastener driving interlocking pistol or tool according toV the present invention.

FIG. 2 is an enlarged fragmentary view corresponding to FIG. 1, with the pistol open lso that the cartridge may be loaded therein.

FIG. 3 is an enlarged fragmentary View showing how the adjustment or control of the power may he effected.

FIG. 4` is a View corresponding to FIG. 3 of a modified form of the device according to this invention.

FIG. 5 is a fragmentary sectional view showing a modiried form of the ejection means according to the present invention.

p FIG. 6 is a perspective view showing an attachment member at the barrel muzzle end. Y

FIG. 7 is a sectional view taken along VII-VII in FIG. 1; and

FIG. 8 -is a perspective view showing the arrangement of the magnets around the pistol barrel. p p

Referring to the drawings, there is shown a cartridge holder 1 on which -a breech 2 is screwed by means of an externally threaded part 3.

A guiding cylinder 4 adapted to guide a piston 5 is held in an adjustably xed position by means of threads 6 in a sleeve 7, which is in turn, screwed on the cartridge holder 1.

There is provided a knurled internally threaded ring 1t) adapted to `lock the cylinder 4 relatively to the sleeve 7. Said ring 1d bears an adjusting mark 11 which cooperates with a scale 12 on the cylinder 4, to permit accurate adjustment of the position of the cylinder 4 relatively to the sleeve 7.

An internally threaded end part 13` of the cylinder 4 supports a tube 14 which acts as a guide for the fastener or stud when ring occurs. Said tube 14 is extended inwardly of the pistol by a cage 15 provided with a cap 16 made from nonrnagnetic material and containing magnets 17.

The tube 14 comprises also hollow screws 18 containing magnets 19, the right hand ends of which (viewing FIG. 1) are flush with the bottom of a recess 20 provided at the pistol barrel muzzle end for a purpose discussed later.

The barrel muzzle end of the pistol or firing tool is also provided with a flash shield 21 as a protection against possible ricochets and spalling of the workpiece material, said shield being made from a plastic material such as Rilsan. A tubular casing or socket 22, screwed on the breech 2 at 23, Ais slidingly mounted over the sleeve'7, thus guiding the front part of the pistol when opening the breech, as shown in FIG. 2.

Said socket 22 is provided with orifices 24 and 25 through which, when open, a new cartridge may be loaded and the spent cartridge case removed.

An outer casing 26 fixed to sleeve 7 surrounds the socket 22.and covers the orifices 24vand 25, and limits the movement of the front part of the pistol by means of its shoulder 27 which engages a shoulder 28 provided at Y the front end (viewing FIG. 2) of tubular element 22.

Owing to safety reasons, the pistol or tool organization .i

is such that it is necessary (1) to make use of a manual force on a hand grip 34 in the direction of arrow 35, sor,

35, and the manual pressure in the direction Yof arrow 36 Y on the lever 37 to release the stub 3S), said trigger is in a condition to release the fin'ngpin 29 and'thus to re Y the pistol cartridge.

The drawings show clearly how the part integral with the hand grip 34 slides on the breech 2.

A stub 39, which is integral with the hand grip 34, moves in a groove 40 cutin the rear part of the breech 2 and constrains the latter against any relative movement of rotation with respect to the hand grip 34.

The cartridge holder 1 is provided with a pair of holes 41 in which are slidingly mounted ejector pins 42 urged leftward or backward by ejector pin spn'ngs 43.`

Screws 44 are provided respectively not only to limit the travel ofthe extractor pin 42 but also to lock the same against .any rotation.Y Y

In the pistol or tool form illustrated in FIG. 5, the cartridge extraction isy merely effected by means of a small plate 45 screwed on the breech 2 inside the same, and below lwhich is engaged the outside periphery of a cartridge 46, as seen in FIG. 5.

Thus, `it can be understood that upon opening ofthe i breech 2, said cartridge V46 is withdrawn from the bore thereof.

FIGS. 3 and 4 show at an enlargedl scale how is effected the power adjustmentror control according to the present invention.

In the form shown in FIG. 3, the piston which slides within the cylinder 4 is extended at the rear thereof (viewing FIG. 3) by a cylindrical rod 47, the free tapered end 48 of which terminates in a concave cup-shaped recess 49,.

The distance between the piston 5 and the end 49 of the rod 47 is such that,'regardless'of the position of the cylinder 4 with respect to the breech holder, said end 49 of rod 47 bears on a shoulder 50 cut in the cartridge holder 1. Y

It should be particularly noted that the tapered end 48 of the rod 47 shows substantially the same tapering as does the breech-holder corresponding part, but that said two tapered parts do not engage one with the other so as so avoid any jamming.

There 'has `been shown in solid lines the position of guiding cylinder 4 corresponding to the lowest power of the device (i.e. to the adjustment used to drive studs or the like into relatively soft materials), while the position of said guiding cylinder 4`is shown in phantom lines in the case of a maximum power adjustment (i.e. to drive studs or the like into hard materials). s

.Itis to be understood that the section of the free space between the end 52 ofA cylinder 4` and the cor-responding part of the cartridge holder lvariesY as said cylinder is in a path as shown by the arrows in FIG. 3, such gas es-Y cape being consistent over the whole inside periphery of the Iguiding cylinder. 4 and'said gases being at last dis. charged to the surrounding atmospherethrough baffles 53 (FIG. v1) which avoid excessiveV noise. Y

j The non evacuated gas part causes the piston lunit to be propelled forwardly within cylinder 4, a pistonv sealing 1ing754 being provided in a circular groove cut in said piston to avoid gas leakage. v

' When the piston 5 Vpasses beyond anporifice orl hole 55 drilled in cylinder 4, the gaseswhich propelled said piston are then led outside to the atmosphererthrough'the baies 53. Y

A rubber tubular element 56, which is used as abrakie for the piston, is driven to engage a washer 57 made from a resilient plastic material such as, e.g. polyvinyl chloride.

According to the present invention, saidrwasher 57 is disposed between the rubber tubular element 56 acting as a buffer or shock-absorber and the pistol tube 14, thus avoiding a premature wearing of the buffer 56.

When the piston unit 5 is propelled forwardly under the tiring action, a rod 58 which is integral therewith drives the fastener or stud into the workpiece material.V

It can be seen that the effective space left available for gas iow between the guiding cylinder 4 and the cartridge holder 1 determines on the one hand the amount of gases acting effectively on the piston 5 and used to drive inthe stud, and on the other hand the amount of gases ledV directly to the outside atmosphere.

In the second form of the fastener driving pistol Vaccording to this invention shown in FIG. 4, the tapered end Y48 of rod 47 is provided with a cylindrical extension 48a:V

extending into the iiring chamber 51. e f. In said pistol form, the piston 5 bears, before ring,

. against the bottom of cylinderV 4 which acts as a guide for the piston7 but said tapered portion y48 of rod 47 never moves to engage the corresponding tapered portion ofthe cartridge holder, thereby avoiding any jamming thereof.

There is shown in Ysolid lines in FIGURE 4 the cylinder and piston positions corresponding to the minimum power, and in phantom lines the pistol ladjustment corresponding to the maximum power.

In this pistol form, it can be seen, upon ring a cartridge, that the tiring chamber comprises a closed space which opens to the outside after a small vmovement of the piston 5. I

In the structure corresponding to FIG. 4, the initial ring chamber volume varies as a function of said adjustment, owing to the fact that, prior to firing, the piston 5 bears always on the bottom of cylinder 4. Consequently, when said adjustment is made to correspond to a low power, the firing chamber comprises at the moment of firing a greater volume compared to the volume that said chamber comprises when the adjustment is madeto correspond to the maximum power.

Now, it is well known that the lower the tiring chamber volume the higher the power of a cartridge. v

It can be seen easily that in this second pistol form according to the present invention, power adjustment is effected by two effects, namely (l) varying the initial firing chamber Volume, and (2) varying the cross-section area available for gases flowing directly to the surrounding atmosphere.

Thus, with .the fastener driving pistol or tool accordingV tubel4 in a housing or recess made from a non magnetic metal.

Said magnet organization is shown in FIGS. 7. and 8. l

. There can be seen in the sectional view in FIG. 7 the aforementioned cage 15 and the pair of cylindrical inagnets 17 housed within bores drilled in the cage.

FIG.-8 shows said magnets 17 held by means of the recitedrcap 16 within bores 17a drilled in said cage 15. v Y With suchan organization, the magnetsengage directlyv the fastener or stud andvinsure effectively the holding y thereof. f Y

On the other hand, said magnets have a sufficient clearance to freely pass the rod V58 integral with piston 5 which propels forwardly the studl 59 upon firing ofthe pistol.l

According to the present invention, there is provided also a pair of magnets 19 at the bottom of the housing or recess located at the barrel muzzle end, said magnets being contained within hollow screws 18 maintaining the attachment member 60' which is to be xed to the workpiece by means of the fastener or stud.

In FIG. 6 there is shown in perspective the barrel muzzle end Without the flash shield 21. It can be seen in this iigure how the attachment member 60 is held by the magnets in the corresponding recess 20 and may be thus in a xed position when the fastener or stud is propelled upon ring the pistol cartridge.

It is to be understood that many modications and arrangements of parts may be designed by those skilled in the art without departing from the scope of this invention as illustrated and defined in the appended claims.

What I claim is:

1. An explosion-actuated fastener-driving tool having a barrel for receiving a fastener to be driven, a breech block dening a ring chamber, cylindrical means deining a piston chamber between said barrel and ring chamber, and piston means slidable in said piston chamber between a rear position in which said piston means closes one end of said firing chamber and a forward position axially removed therefrom, said cylindrical means comprising a transverse wall portion mounted for axial adjustment relative to said breech block, said adjustable wall portion constituting a rear wall for said piston chamber through which one end of said piston means projects and defining with the forward part of the tiring chamber Wall an adjustable vent by-passing said piston chamber through which the forward end of said ring chamber is connected to the exterior of the tool, said vent being blocked by said piston means when it closes said ring chamber but progressively opened by said piston means as it moves forward.

2. A tool as claimed in claim 1 comprising also means for locking said adjustable wall portion in any of a plurality of positions relative to said breech block.

3. A tool as claimed in claim 1 in which said firing chamber opens at its forward end into an axial bore which tapers inwardly toward said ring chamber, and the rear surface of said adjustable wall portion is tapered to project into said bore, the rearward end of said piston means being less sharply tapered than at least part of said bore and extending completely therethrough to close the forward end of said tiring chamber when said piston is in its rear position. v

References Cited in the tile of this patent UNiTED STATES PATENTS 1,569,153 Temple Jan. 12, 1926 1,854,374 Romberg et al. June 2l, 1932 2,096,002 Moreira et al. Oct. 19, 1937 2,132,148 Davis Oct. 4, 1938 2,258,861 Park et al Oct. 14, 1941 2,632,890 Tietig Mar. 31, 1953 2,660,726 Weingart Dec. 1, 1953 2,671,484 Clark Mar. 9, 1954 2,724,116 Termet Nov. 22, 1955 2,778,020 Erickson Ian. 22, 1957 2,790,173 Henning et al. Apr. 30, 1957 2,801,416 Evans Aug. 6, 1957 2,930,042 Temple et al. Mar. 29, 1960 FOREIGN PATENTS 325,204 Switzerland Dec. 14, 1957 744,822 Great Britain Feb. 1-5, 1956 1,174,052 France Nov. 3, 1958 

